1. Field of the Invention
The present invention relates to a silver halide color photographic light-sensitive material, and more particularly to a silver halide color photographic light-sensitive material which has excellent color-image fastness.
2. Description of the Related Art
Photographically usable reagents which are slightly soluble in water include oil-soluble couplers, anti-oxidants for preventing color-fading, color-fogging, and color amalgamation (such as alkyl hydroquinones, alkyl phenols, chromans, and coumarones), membrane-harding agents, oil-soluble filter dyes, oil-soluble UV absorbers, oil-soluble fluorescent whitening agents, DIR compounds (such as DIR hydroquinones and colorless DIR couplers), developers, dye developers, DDR redox compounds, and DDR couplers. They are dissolved in a suitable oil-forming agent, i.e., a solvent with a high boiling point (b.p.). The dissolved reagents are dispersed in a hydrophilic organic colloidal solution, particularly in a gelatin solution, in the presence of a surfactant. In the dispersed state, they are contained in a hydrophilic organic colloidal layer (such as a light-sensitive emulsion layer, a filter layer, a backing layer, an antihalation layer, an intermediate layer, and a protective layer). As the solvent with a high boiling point, phthalic ester compounds and phosphoric ester compounds are generally used.
Esters of phthalic acid and esters of phosphoric acid are organic solvents having a high-boiling point, and have been widely used due to their excellent ability of dispersing couplers, good affinity with colloidal systems such as of gelatin, contribution to the stability of developed colors, contribution to the hue of developed colors, chemical stability when they are included in light-sensitive materials, and availability at low costs.
However, these known high b.p. organic solvents (for example, phthalic esters containing alkyl groups and phosphoric esters containing alkyl groups) are not yet satisfactory for use in recent light-sensitive materials, for which high performance is required, because they are insufficient to prevent fading of color images due to light, heat and humidity, and the generation of stains. For example, high b.p. organic solvents comprising an alkenyl group disclosed in JP-A-59-149,348 and JP-A-57-173,835 have effects insufficient to prevent fading of color images due to light, heat and humidity, and the generation of stains.
It has been desired to overcome these drawbacks, in particular for a silver halide color photographic light-sensitive material comprising a support having thereon one or more layers including at least one light-sensitive silver halide emulsion layer comprising at least one diffusion-resistant coupler which undergoes a coupling reaction with an oxidized product of an aromatic primary amine developer to form a dye.
An object of the present invention is to provide a silver-halide color light-sensitive material which provides color images which are stable against heat, humidity, and light, and which generates less stains.
Another object of the present invention is to provide a silver-halide color light-sensitive material which has excellent color developing capability.
A further object of the present invention is to provide a silver-halide color light-sensitive material comprising a high boiling point organic solvent which has a great ability of dissolving organic materials such as dye-forming couplers and having excellent effects in preventing color fading of dyes formed as a result of coupling reaction with an oxidized product of an aromatic primary amine developer.
It has now been found that these and other objects can be achieved by a silver halide color photographic light-sensitive material comprising a support having thereon one or more layers including at least one light-sensitive silver halide emulsion layer comprising at least one coupler which undergoes a coupling reaction with an oxidized product of an aromatic primary amine developer to form a dye, wherein at least one of the layer(s) on said support comprises at least one compound represented by the following formula (I): 
wherein R1 represents C3-C14 linear or branched unsubstituted alkenyl, R2 represents alkyl, cycloalkyl, C3-C14 linear or branched unsubstituted alkenyl, R3 represents a group capable of being substituted on the benzene ring, and m represents an integer from 0 to 4. (In the specification, Cp-Cq means having from p to q carbon atoms(p,q: numbers).)
It has also been found that, when both R1 and R2 in formula (I) are C3-C14 unsubstituted alkenyl represented by formula (II), the above objects are more effectively achieved. 
wherein R4 represents hydrogen or unsubstituted alkyl, and A represents alkylene or alkenylene composed merely of carbon and hydrogen atoms (hereinafter, the alkenyl group represented by formula (II) is referred to as xe2x80x9cterminal alkenyl groupxe2x80x9d).
It has also been found that, when both group R1 and R2 in formula (I) are terminal alkenyl groups, which are represented by formula (II), the above objects are more effectively achieved.
The present invention will next be described in detail.
When the substituents in formula (I) contain aliphatic moieties, these aliphatic moieties may be linear, straight, or cyclic, and saturated or unsaturated, and substituted or unsubstituted if there is not any other indication. However, the alkenyl groups in R1 and R2 are not substituted.
When the substituents in formula (I) contain aryl moieties, these aryl moieties may be substituted or unsubstituted, and may form a single ring or a condensed ring.
When the substituents in formula (I) contain heterocyclic moieties, the hetero atoms which form the rings of the heterocyclic moieties may be nitrogen, oxygen, or sulfur, and each ring may preferably have 5-8 members. Carbon atoms and nitrogen atoms on the ring may be substituted or unsubstituted, and the ring may be a single ring or a condensed ring.
In formula (I), the C3-C14 linear or branched, unsubstituted alkenyl as R1 or R2 is preferably a xe2x80x9cterminal alkenylxe2x80x9d group, which is represented by formula (II). 
In formula (II), R4 represents hydrogen or alkyl (preferably C1-C12 alkyl), more preferably hydrogen or methyl, and more preferably hydrogen. The symbol A represents alkylene (preferably C1-C12 alkylene) or alkylene (preferably C2-C12 alkenylene) which is merely composed of hydrogen and carbon atoms.
Among the alkenyl groups represented by R1 and R2, the xe2x80x9cterminal alkenylxe2x80x9d groups of the following formula (III) are preferred. 
wherein R5 and R6 respectively represent hydrogen, C1-C4 unsubstituted alkyl, or C2-C4 unsubstituted alkenyl, A1 represents a single bond C1-C10 unsubstituted alkylene or C2-C10 alkenylene, R4 has the same meaning as defined in formula (II). R5 and R6 are preferably hydrogen, methyl, ethyl, or vinyl, with hydrogen being particularly preferred.
Specific examples of the alkenyl groups represented by R1 and R2 are listed below, which should not be construed as limiting the invention thereto. 
If the alkenyl groups have geometrical isomers, they may be composed merely of either one of cis- or trans-, or may be a mixture of them. Among the above-listed species, the xe2x80x9cterminal alkenylxe2x80x9d groups represented by the following a), c), d), e), n), l), p), q), r), s), and u) are preferred.
In formula (I), R2 may be C1-C30 alkyl (such as methyl, ethyl, isopropyl, t-butyl, chloromethyl, benzyl, octyl, 2-ethylhexyl, 3,5,5-trimethylhexyl, decyl, dodecyl, isotridecyl, and 2-hexyldecyl), C3-C30 cycloalkyl (cyclopropyl, cyclopentyl, and cyclohexyl), C6-C30 aryl (for example, phenyl and 2-naphthyl), as well as C3-C14 linear or branched, unsubstituted alkenyl (the same as R1). R2 is preferably unsubstituted alkenyl.
In formula (I), R1 and R2 are preferably unsubstituted alkenyl as described above. R1 and R2 are more preferably C3-C10 unsubstituted alkenyl, and most preferably C3-C8 unsubstituted terminal alkenyl. Specifically, the alkenyl groups represented by a), b), c), d), e), h), l), p), q), and u) are preferred, with a), d), l), h), and q) being particularly preferred.
In formula (I), it is preferable that groups R1 and R2 are the same. Moreover, the group xe2x80x94COOR2 is preferably at the ortho- or para-position relative to the group xe2x80x94COOR1, and more preferably at the ortho-position.
In formula (I), R3 represents a group which is capable of being substituted on the benzene ring. Preferably, R3 is a C1-C30 aliphatic group (such as methyl, t-butyl, allyl, cyclohexyl, and benzyl), C6-C30 aryl (such as phenyl or 2-naphthyl), C2-C30 aliphatic oxycarbonyl (such as methoxycarbonyl and allyloxycarbonyl), C1-C30 carbamoyl (such as N-methylcarbamoyl and N,N-dioctylcarbamoyl), halogen (such as chlorine, bromine, and fluorine), cyano, C1-C30 acylamino (such as acetamino and benzoylamino), and C1-C30 alkoxy (such as methoxy and 2-ethylhexyloxy) and the like. Among them, an aliphatic group, aliphatic oxycarbonyl, carbamoyl, alkoxy and halogen are preferred. Alkenoxycarbonyl is more preferred, and allyloxycarbonyl is particularly preferred. (The two types of oxycarbonyl are included in aliphatic oxycarbonyl.)
The character m represents an integer from 0 to 4, preferably 0 or 1, more preferably 0.
When m is 1 or 2, a combination is preferred in which R3 is allyloxycarbonyl and R1 and R2 are both allyl.
When m is 4, R3 is preferably halogen.
In this connection, when m is not less than 2, a plurality of R3 may be the same or different from each other, and may be linked to each other to form a ring.
Among the compounds of formula (I) according to the present invention, particularly preferable ones are represented by formula (IV). 
wherein A1, R5, and R6 have the same meaning as defined in formula (III), and R4 has the same meaning as defined in formula (II). R31 is alkenoxycarbonyl and m1 is 0 or 1.
Specific examples of the compounds of formula (I) according to the present invention are shown below, which should not be construed as limiting the invention thereto. 
Some of the compounds (I) which are used in the present invention are commercially available. For example, S-1 is obtainable from Tokyo Chemical Industry Co. and Daiso Co., Ltd, and S-2 is obtainable from Wako Pure Chemical Industries Co.
If not commercially available, other species of formula (I) can be synthesized, with high yield, by a known reaction such as an esterification reaction of a carboxylic chloride or carboxylic anhydride and an alcohol or an esterification reaction, in the presence of an acid catalyst, between a carboxylic acid and an alcohol (see, for example, New Experimental Chemistry Course 14 II, pp. 1002-1062, published by Maruzen, Japan).
The compound (1) in the present invention is contained in at least one layer on a support, which is preferably a hydrophilic colloidal layer. More preferably, the compound (I) in the invention is contained in a silver halide emulsion layer containing at least one of a dye-forming diffusion-resistant coupler mentioned above.
The compounds of formula (I) according to the present invention primarily function as high b.p. organic solvents. The term xe2x80x9chigh b.p.xe2x80x9d refers to a boiling point of not less than 175xc2x0 C. under atmospheric pressure. The amount of the compound of formula (I) in use may vary depending on an intended purpose, and is not particularly limited. It is preferably from 0.0002 g to 20 g, more preferably from 0.001 g to 5 g, per m2 of a light-sensitive material. Generally, the weight ratio of the amount of compound (I) to the total amount of the photographically usable reagents such as couplers is within the range from 0.01 to 8, more preferably from 0.01 to 4, and most preferably from 0.05 to 2.
The weight ratio of the amount of a dispersion composed of the compound of formula (I) and photographically usable reagents such as a coupler to the amount of a dispersion medium is usually from 2 to 0.01, and preferably from 1.0 to 0.05. Typical example of the dispersion medium includes gelatin. Hydrophilic polymers such as polyvinyl alcohol can also be used. The dispersion in the present invention may further contain a variety of optional components other than the compounds (I) of the present invention and photographically usable reagents.
The compound of formula (I) may be used in combination with any other conventionally known high b.p. organic solvent. When the known high b.p. organic solvent is co-used, the amount of the compound (I) of the present invention is preferably from 5 to 100% by weight, more preferably from 10 to 70% by weight, and most preferably from 20 to 60% by weight of the total amount of the high b.p. organic solvents.
Examples of the high b.p. solvents which may be used in combination with the compound (I) of the present invention are described, for example, in U.S. Pat. No. 2,322,027. Specific examples of the high b.p. organic solvents with a boiling point of 175xc2x0 C. or higher under atmospheric pressure include phthalic esters (such as dibutylphthalate, dicyclohexylphthalate, di-2-ethylhexylphthalate, decylphthalate, bis(2,4-di-tert-amylphenyl)phthalate, bis(2,4-di-tert-amylphenyl)isophthalate, bis(1,1-diethylpropyl)phthalate, phosphoric or phosphonic esters (such as triphenylphosphate, tricresylphosphate, 2-ethylhexyldiphenylphosphate, tricyclohexylphosphate, tri-2-ethylhexylphosphate, tridodecylphosphate, tributoxyethylphosphate, trichloropropylphosphate, and di-2-ethylhexylphenylphosphonate), benzoic esters (such as 2-ethylhexylbenzoate, dodecylbenzoate, and 2-ethylhexyl-p-hydroxybenzoate), amides (such as N,N-diethyl dodecaneamide, N,N-diethyl laurylamide, and N-tetradecylpyrrolidone), sulfonamides (such as N-butylbenzene sulfonamides), alcohols or phenols (such as isostearyl alcohol and 2,4-di-tert-amylphenol), aliphatic carboxylic esters (such as bis(2-ethylhexyl) sebacate, dioctyl azelate, glycerol tributyrate, isostearyl lactate, and trioctyl citrate), aniline derivatives (such as N,N-dibutyl-2-butoxy-5-tert-octylaniline, etc.), hydrocarbons (such as paraffin, dodecylbenzene, and diisopropyl naphthalene), and chlorinated paraffins. Useful auxiliary solvents include organic solvents with a boiling point of 30xc2x0 C. or more, preferably a boiling point within the range from 50xc2x0 C. to approximately 160xc2x0 C. Typical examples of the auxiliary solvents include ethyl acetate, butyl acetate, ethyl propionate, methylethylketone, cyclohexanone, 2-ethoxyethylacetate, and dimethylformamide.
Examples of the light-sensitive material and dye-forming coupler which are used in the present invention are listed, for example, in JP-A-62-215,272, JP-A-2-23,144, and EP 355,660 A2, which are incorporated herein by reference.
A diffusion-resistant coupler can be used as a coupler essential to the present invention. The diffusion-resistant coupler is a dye-forming coupler which preferably has a substituted or unsubstituted aliphatic or aryl group which has 8 or more, preferably 10 or more, more preferably 12 or more, most preferably 14 or more carbon atoms, in any moiety thereof, so as to prevent ambiguity or blur of a color image due to transfer, in a film, of the dye-forming coupler in the film or a formed dye.